1. Field of the Invention
This invention relates to nursing systems for feeding liquids to infants and small children. More specifically, this invention relates to a variable flow infant feeding assembly that is designed so that a caregiver can select an optimal feeding flow rate without having to change nipples, as may be desired depending upon the age and appetite of the infant as well as the liquid that is being dispensed.
2. Description of the Related Technology
Nipple members for baby bottles typically have a circular mounting flange portion and a nursing portion that is designed to fit in an infant's mouth. The two portions are formed together in a single, unitary piece and are fabricated from the same type and grade of flexible material, usually latex, vinyl, silicone or thermoplastic elastomers (TPE's). Nipple member types having different design flow rates and hole configurations for dispensing different types of liquids are widely available. As an infant grows, she or he will learn and expect to drink faster, and nipple manufacturers sell different types of nipple members to accommodate this. Different nipple member types tend to end up mixed in a single container, and a caregiver will have to search each time for the desired type of nipple member, frequently (as any caregiver who has given a midnight feeding will attest) in dim light. Some identifying legend is usually embossed on the rim, but it can be very difficult to read. Some nipples are color-coded, which makes them easier to identify.
Most baby bottles are configured so that a ring member having a large hole defined therein screws on to the baby bottle to seat the mounting flange of the nipple member against the upper lip of the bottle. In order to permit replacement air to enter the baby bottle during feeding, it is typical for nipple members to have one or more ventilation holes defined in the mounting flange. The ring member is typically designed so as not to create an airtight seal with the upper surface of the mounting flange in the area that is close to where the mounting flange transitions into the feeding portion of the nipple member. Accordingly, replacement air will enter the baby bottle through a gap that is defined between the upper surface of the mounting flange of the nipple member and then through the ventilation holes.
U.S. Pat. No. 3,735,888 to Jacko discloses a baby bottle having an adjustable valving structure that is positioned at the bottom end of the baby bottle, opposite from the feeding end, for adjusting the amount of ventilation air that is permitted to enter the baby bottle during feeding, thereby permitting the feeding flow rate to be adjusted. However, this design apparently never achieved widespread commercial acceptance, possibly because of issues of leakage at the bottom of the baby bottle.
Clearly, it would be advantageous to caregivers and product manufacturers alike if a workable system for permitting feeding flow to be varied without changing nipples could be developed. A need exists for an improved infant feeding system that is able to reliably, inexpensively and hygienically provide variable feed flow rate options to caregivers without necessitating changing components such as nipples.